class ChatModel {
  final String username;
  final String message;
  final String imageUrl;

  ChatModel({
    this.username = "",
    this.message = "",
    this.imageUrl = "",
  });
  //工厂
  factory ChatModel.fromMap(Map map) {
    return ChatModel(
      username: map["username"],
      message: map["message"],
      imageUrl: map["imageUrl"],
    );
  }
}
